#inlclude <cstdio>
#include <sstream>
using namespace std;
int a(int ax,int b) {
	int i,j=1;
	int sum=1;
	for(i=b; j<=ax; i--) {
		sum*=i;
		j++;
	}
	return sum;
}
int c(int ax,int b) {
	sum=a(ax,b);
	for(i=1; i<=ax; i++) {
		sum/=i;
	}
	return sum;
}
int Catalan(int n) {
	return c(n,n*2)/(n+1);
}
int main(int argc,char* argv[]) {
	int n;
	if(argc==2){
        stringstream s;
        s << argv[1];
        s >> n;
	}
	else{
		scanf("%d",&n);
	}
	printf("%d",Catalan(n));
	return 0;
}
